The inventive concept relates to a substrate structure, a complementary metal oxide semiconductor (CMOS) device including the substrate structure, and a method of manufacturing the CMOS device.
Research has been actively conducted to develop compound semiconductors such as devices using Periodic Table group III-V semiconductor materials. Since the electron mobility of group III-V compound semiconductor materials is equal to or greater than about 10 times to 1,000 times the electron mobility of silicon (Si), group III-V compound semiconductor materials are used in CMOS devices to form high-speed channels or high-efficiency solar cells.
Group III-V substrates such as InP, GaAs, GaSb, or InSb substrates are widely used to grow group III-V semiconductor materials thereon. However, such substrates are expensive as compared with Si substrates and are easily broken during processing, and it is difficult to manufacture such substrates having a large area. For example, the maximum commercially available size of such substrates is about 6 inches. For this reason, semiconductor devices using Si substrates instead of group III-V substrates are being developed.
In addition, there is recently increasing interest in technology for realizing silicon-based photonics integrated circuits; and, along with this, there is increasing demand for technology for forming devices, such as light sources (e.g., light emitting diodes (LEDs) and laser diodes (LD)) and transistors for high-speed devices, on Si substrates by using group III-V compound semiconductor materials. If group III-V compound semiconductors are integrated on large-area Si substrates, processes of the related art for producing silicon may be used, and costs may be reduced.
However, due to the lattice constant difference and thermal expansion coefficient difference between group III-V compound semiconductor materials and Si substrates, various defects are present, and thus there is a limit to the applications for such devices. For example, if a semiconductor thin film having a lattice constant smaller than that of a substrate is grown, dislocation may be caused by compressive stress; and, if a semiconductor thin film having a lattice constant greater than that of a substrate is grown, cracking may be caused by tensile stress.
In addition, technology for growing germanium (Ge) on a Si substrate has been developed to form p-type metal oxide semiconductor (MOS) devices. Since germanium (Ge) has a high degree of hole mobility and a small energy band gap, the use of germanium (Ge) may reduce power consumption. A high-quality germanium (Ge) crystal growing method applicable to mass production, however, may be needed for practical use of germanium (Ge) in such applications.